Fireplace



w. RUEGG FIREPLACE May 4, 1965 2 Sheets-Sheet 1 Filed March 28, 1962 Fig. 1

2 Sheet s-Sheet 2 w. RUEGG FIREPLACE Fig. 5

May 4, 1965 Filed March 28, 1962 United States Patent O M 3,181,526 FEREPLACE Walter Riiegg, Chapfstrasse 541, Zurnilron, Zurich, Switzerland Filed Mar. 28, 1962, Ser. No. 183,169 Claims priority, application Switzerland, Mar. 29, 1961, 3 ,7 46 61 3 flairns. (Cl. 126-133) The present invention relates to fireplaces and more particularly to a fireplace which includes a heating device along which pass the combustion gases. The heating device may serve to produce hot air or it may consist of a water heating apparatus which is adapted for connection to a radiator or a radiator system.

It is known to fit a tube system into the throat of a fireplace which serves as an outlet for the fire combustion gases of the sleeve-like casing of the fireplace and to use it e.g., for the production of hot air or to connect it to the conduit system of an existing central-heating plant, or to one or more radiators suitably disposed in the room. The heat utilization in such a known heating system, however, is insufficient in most cases. Or the one hand, the heat exchange surface, frequently, is not very large, since it is not possible to dispose tubes or air ducts of any desired length in the narrow throat of the fireplace. On the other hand, the heating of the wall which surrounds the hearth of the fireplace and the heat reflection from this wall withdraws relatively much heat from the fire gases.

The fireplace according to the invention comprises a hearth having at least one boundary wall thereof formed as a metallic heat exchanging element, e.g., as a hollow jacket made of metal (sheet-steel or cast iron). Advantageously, the heat exchanging element is swept by the fire gases at least partly also on its external wall remote from the hearth.

An advantageous utilization of heat is obtained by directly defining and partly encompassing the hearth by the heat exchanging element, e.g., by a boiler. It can be improved still more when a portion of the ascending fire gases is guided upwards along the insulated rear wall of the element. By arranging an adjustable bafile plate of suitable shape in the throat of the fireplace casing, the guidance of the escaping fire gases can be additionally improved by the provision of an increased contact with the outer surfaces of the heat exchanging element.

The normally poor heat utilization in a fireplace results from the fact that combustion is effected with a great excess of air and thus leads to a relatively substantial cooling of the fire gases. As long as the hot fireplace is used for burning wood only, and as a subordinate source of heat, this excess of air and thus the economy in heating is of little importance. However, when a boiler or an air heating device is installed, which ensures a particularly good utilization of the heat contained in the fire gases, as in the present invention, it is possible to build the fireplace so that it can use, in addition to wood, coal or oil as fuel. When the fireplace is to be used as part of a central heating system one should prevent the infiux of a great excess of air, such as is unavoidable with the relatively large fireplace-openings for the excess air cools the hot fire gases to an undesired degree. Accordingly, it is desirable to provide a closure wall of transparent material, by means of which the fireplace opening can be closed entirely or partly. In addition, there should be provided separate air supply means adapted to the particular type of fireplace, such as, for example, air supply ducts with control flaps which open from below into the hearth. It will thus be possible to obtain a heat utilization in the heating system as is usual for the conventional hot water or hot air heating plants. A fireplace built in Patented May 4, 1965 the described manner can be used as single fire box of a central hot water or hot air heating system in one-family houses, vacation-homes and thelike.

The present invention will now be described in more detail with reference to the accompanying drawings illustrating, by way of example, several embodiments of the invention, and in which:

FIGURE 1 is a vertical sectional view of a first embodiment of a fireplace according to the invention including a hot water heating system, i

FIGURE 2 is a cross-sectional view taken in the zone of the fireplace opening of the embodiment of FIGURE 1,

FIGURE 3 shows a vertical section on the line III-III of FIGURE 2,

FIGURE 4 is a vertical section, similar to that shown in FIGURE 1, through a second embodiment of a fireplace provided with a hot water heating system,

FIGURE 5 is a vertical section, similar to that shown in FIGURE 1, through a third embodiment of a fireplace provided with a hot water heating system, and

FIGURE 6 is a vertical section, similar to that shown in FIGURE 1, through an embodiment of a fireplace having a hot air heating system.

In FIGURES 1 to 3 the numeral 1 designates the bottom plate of the fireplace incorporating the hearth 2. The bottom plate 1 is supported by a pedestal 3 which has an opening communicating with the hearth 2. In the example shown an oil-cup burner 5 is inserted in the bottom plate opening on the hearth 2. Underneath burner 5 there is an oil pan 6 accessible from the front side of the fireplace within the opening 4 of the pedestal. A motor driven oil burner may also be installed in place of the cup burner 5. When wood is used as fuel, the burner 5 may be covered, e.g., by means of a cast iron cover insulated by an asbestos sheet. However, it is also possible to replace the burner 5 by a grate and the oil pan by an ash drawer, so that coal can be used for heating.

Between the external wall 7 and the actual outer jacket 8 of the fireplace made of firebricks, the chimney 9 extends upwards parallel to the throat Ill. The inner wall of the fireplace is formed by a hollow jacket 11 fabricated from sheet steel. This hollow jacket 11 is connected by delivery and return conduits 12 to a radiator system, not shown, but which is provided in the room or the rooms to be heated, and represents the boiler of the hot Water heating system thus provided. As it will be seen from the drawing, the rearward portion 11a of the heating jacket 11 does not extend all the way down to the bottom plate 1. It is also spaced from the adjacent wall of the external jacket 8. Furthermore, the two lateral sections of jacket 11 along a portion of their width are spaced from the adjacent wall of the outer jacket 8 so that there is provided for a portion of the fire gases a rear flue duct 13 which communicates with the hearth and also with the throat 10 of the fireplace. In this manner a major portion of the outer surface of hollow jacket 11 can be contacted by the rising fire gases. In order to additionally enlarge the surface area of the boiler or jacket 11 which is contacted by the fire gases, there are provided in flue duct 13 three boiler pipes 11b, the ends of which open into the lower or upper part of the jacket 11. Horizontally extending boiler tubes may also be provided though, of course, upwardly extending tubes least impede a perfect discharge of the due gases.

In the zone of the upper end of the boiler or jacket 11, there is pivotally mounted a control and closure flap 14 which is upwardly curved in its closed position closure flap 14 can be actuated in a manner not shown but known per se, e.g. by means of a chain pulling arrangement or a link rod. Flap 14 is formed and disposed so that with an open discharge aperture, but particularly 'by lateral sections to a hollow jacket.

7 with a slightly restricted discharge opening, the the gases which rise. in front of the rearward boiler section 11a arev somewhat restricted, and the fire gases rising in the rear flue duct 13 are at least partly deflected in forward direction. Accordingly'a large portion of these fire gases,

afterhaving intensively contacted the boiler walls, escape past the front side of the flap 14 into the chimney.

Thus, if the front opening of the fireplace is open and most of the cold air entering this opening flows upwardly, this coldair is dammed below the front jacket portion 11c andthus remains for a longer time within the combustion-space with the effect that this air is heated up by the gases before it contacts the jacket portion 11c. Without such damming effect the cold air'would rise directly up to the front vessel portion 110 and would cool this portion. v

In order to avoid the undesired large excess of air during combustion which would result from an unimpeded cold air" supply through the large opening '0f the fireplace, there are provided two plates a, 15b 'of transparent heatrresistant material, e .g. heat-resistant safety glass, in the opening of the fireplace. The top plate 15a is fixed, while the bottom plate 15'!) is held in lateral guides 16 and, upon exposing the lower half of the fireplace opening, can be moved from its closure position shown in FIGURE 1 in upward direction and locked in that place. In order to adjust the supply of fresh air' admitted through the. fireplace opening to suit the prevailing conditions, the movable Plate 15b'can suitably be locked in different levels. Instead of being adjustable in height, the movable plate 15b could also be arranged I to be displaceable in a lateraldirection. Moreover, the

transparent closureof the opening could'also be formed 'by adjustable transverse or vertical blades or by plates movable in a door-like manner. It is also possible to provide only a single plate which entirely closes or entirely clears the opening of the fireplace.

In the embodiment shown in FIGURE 4, a single plate 150 is provided as an adjustable front closure. Plate 15c is made e.g. of heat proof safety glass and can be moved in lateral vertical guides and locked in its par- .ticular adjusted positions. 7 The heating vessel 11 of the hot water. heating system is constructed in this embodiment in a way similar to that employed in the previously described fireplace. However, in this case the flue starts immediately above the throat of the fireplace. A grate 5c is inserted on the fire side 2 of the bottom plate 1 while an ash drawer 6a isdisposedin the hollow space 4 of'the pedestal. Air supply ducts 17 open through the rear wall of the external fireplace jacket 8 underneath and also above the grate 5a. It is thus possible to maintain a perfect combustion even with a completely closed glass plate 150. This arrangement is particularly suitable for burning coal.

a more or less substantial restriction of passage of the fire gases in the zone of the forward boiler portion 110' a closure.

In the fireplace shown in FIGURE 5, the heating vessel 11 forming the fireplace jacket which is similar to the previously described embodiments is provided with a rearward part 1 1d including boiler pipes 110 and a front boiler part 11]; the two parts 11d and 11 are combined tions'of the boiler 11 do not'downwardly extend to the Also in this case the controlyand' closure flap 14 depending on its adjusted position causes The lateral sec- 7 place.

improves the exchange of heat.

bottom plate, but terminate at the level of the bottom edge of the front boiler part 11c. Accordingly, in this arrangement the boiler ll is not supported by the bottom plate, but is suspended for easy dismounting on brackets 18 secured in the external jacket 8 of the fire- This construction makes it possible that such a boiler can subsequently be mounted into an existing fireplace or can be removed-or exchanged for repair purposes without considerable expense;

As it will be seen "from FIGURES, the entire outer surface of the boiler 11 is contacted by the line gases, since a passage 13b is provided for the gases between the front part 11] and the forward outside jacket sec-' tion of the fireplace. In order to ensure a good heat exchange, the front part 11 ofthe boiler is provided with a top portionjlg which is spaced from a ledge 8a of the fireplace jacket 8, so that the gases which flow upboiler pa-rt 11] and the boiler part 11d, are connected to each other by'flat transverse tubes 11h which additionally V A part-cylindrical deflection-flap 14a is pivotally mounted in the zone of the front edge of the boiler part llgrof the heating vessel. Normally, flap 14a, as shown, is suspendedin its lowermost portion under theinfluence of its dead weight, so as to be in abutting relationship with the top edge of the boiler part 11d, and to project partly into the main gas discharge duct enclosed by the top boiler parts and partly into the rear gas discharge duct 13a which is provided betweenthe boiler part 11d and the, outer jacket 8. Flap 7 14a thus prevents the free flow of fire gases out of these ducts andinto the flue. The flap 14d can be rotated clockwise direction so that it closesthejrea-r gas channel 13a. The discharge to the flue can be totally closed when the flap 14a is pivoted upwards until it abuts against the ledges 8a. In the embodiment according to FIG- URE 5 the glass wall closure of the forward fireplace opening is'f'ormed by aremovable and tiltable window 15d, the latter, however, could also be replaced by a one-piece or'two-piece sash-window as in the previously described embodiments. The fireplaceZ includes a forward portion 1a for burning wood, while its rear portion is adapted for oil firing; the oil burner pot 5 which is associated with an air blower, is closed bya cover 19 when not in use. Cover 19 is forwardly moved over the wood firing portion 1a when the fireplace is operated for oil firing.

According to FIGURE 6, a grate 5a is disposed over the opening da containing the ash drawer 6a, and a cup burner 5 is inserted in a separate bottom opening 4b of the hearth 2. The front closure wall 15c made of glass can be upwardly moved within a corresponding recess 24 in the wall of the" fireplace and fixed in the desired position as in the example shown in FIGURE 4. In cont-radistinction to the previously described examples, the heat exchange element is formed as a metallic wall 29 rearwardly limiting the hearth,.the back side of this wall being ,,provided with ribs 26awhich enlarge the heat exchange surface' The space 21*providedl between the outer jacket 8 and the metal wall 23 communicates on the. one hand with an air supply duct 22 and on the other hand with air distributing channels which open in the room to be heated, but are. not shown in the drawing. The duct 22 which supplies fresh air not only to the space 21, but also to the cupburner 22, is provided with an air delivery blower 23. An adjustable closure flap 14b is provided also in this embodiment in the throat of the fireplace. Owing to the relatively large heat exchange wall which in part can also laterally limit the hearth, and the closure wall 150 for the fireplace opening, a particularly eflicient heat utilization is obtained whereby the fireplace may be operated not only by using wood but also by using coal or oil firing system.

I claim:

1. A fireplace comprising a hearth including a bottom plate, said hearth including a forward portion adapted for wood firing and a rear portion adapted for oil firing, a displaceable cover on said bottom plate for selectively covering the said portions to render the same inoperative, the fireplace further comprising an outer jacket and a heat exchange element adapted for connection to a hot water system, said heat exchange element comprising a hollow metal jacket including a front and rear portion in spaced relation and side portions interconnecting the front and rear portions, means supporting the heat exchange element from the outer jacket to position the heat exchange element in the path of heated combustion gases which are produced during wood firing and oil firing operations, the heat exchange element being supported from the outer jacket such that the rear portion of the hollow jacket terminates at a distance above the bottom plate of the hearth While the front and rear portions are respectively in spaced relation with the said outer jacket to define separate front and rear channels for the passage of combustion gas, said fireplace further comprising discharge duct means in communication with the aforesaid channels for the discharge of combustion gases after the latter have contacted the heat exchange element, and control and closure flap means adjacent said duct means for controlling opening and closing of the said channels, said channel between the rear portion of the heat exchange element and the outer jacket being proximate the rear portion of the hearth to enable combustion gas produced during oil firing to pass at least in part in the latter said channel when the latter is opened by the flap means.

2. A fireplace as claimed in claim 1 wherein said heat exchange element comprises flattened pipes extending transversely between the side portions.

3. A fireplace as claimed in claim 1 wherein said front portion of the heat exchange element has a top portion adjacent said duct means, said control and closure flap means being a member of part-cylindrical shape pivotally supported at the top portion of the said front portion for movement between a first extreme position in which the space between the front and rear portion is blocked and a second extreme position in which the discharge duct means is closed, the part-cylindrical member passing through intermediate positions in which the opening of the channel between the rear portion of the heat exchange element and the outer jacket is progressively varied.

References Cited by the Examiner UNITED STATES PATENTS 1,681,995 8/28 Miles 126-121 1,840,306 1/32 Beecher 22 2,787,997 4/57 Asbury 126-121 2,848,958 8/58 Kolmar 11022 FOREIGN PATENTS 179,683 5/22 Great Britain. 587,970 1 46 Great Britain.

JAMES W. WESTHAVER, Primary Examiner. 

1. A FIREPLACE COMPRISING A HEARTH INCLUDING A BOTTOM PLATE, SAID HEARTH INCLUDING A FORWARD PORTION ADAPTED FOR WOOD FIRING AND A REAR PORTION ADAPTED FOR OIL FIRING, A DISPLACEABLE COVER ON SAID BOTTOM PLATE FOR SELECTIVELY COVERING THE SAID PORTIONS TO RENDER THE SAME INOPERATIVE, THE FIREPLACE FURTHER COMPRISING AN OUTER JACKET AND A HEAT EXCHANGE ELEMENT ADAPTED FOR CONNECTION TO A HOT WATER SYSTEM, SAID HEAT EXCHANGE ELEMENT COMPRISING A HOLLOW METAL JACKET INCLUDING A FRONT AND REAR PORTION IN SPACED RELATION AND SIDE PORTIONS INTERCONNECTING THE FRONT AND REAR PORTIONS, MEANS SUPPORTING THE HEAT EXCHANGE ELEMENT FROM THE OUTER JACKET TO POSITION THE HEAT EXCHANGE ELEMENT IN THE PATH OF HEATED COMBUSTION GASES WHICH ARE PRODUCED DURING WOOD FIRING AND OIL FIRING OPERATIONS, THE HEAT EXCHANGE ELEMENT BEING SUPPORTED FROM THE OUTER JACKET SUCH THAT THE REAR PORTION OF THE HOLLOW JACKET TERMINATES AT A DISTANCE ABOVE THE BOTTOM PLATE OF THE HEARTH WHILE THE FRONT AND REAR PORTIONS ARE RESPECTIVELY IN SPACED RELATION WITH THE SAID OUTER JACKET TO DEFINE SEPARATE FRONT AND REAR CHANNELS FOR THE PASSAGE OF COMBUSTION GAS, SAID FIREPLACE FURTHER COMPRISING DISCHARGE DUCT MEANS IN COMMUNICATION WITH THE AFORESAID CHANNELS FOR THE DISCHARGE OF COMBUSTION GASES AFTER THE LATTER HAVE CONTACTED THE HEAT EXCHANGE ELEMENT, AND CONTROL AND CLOSURE FLAP MEANS ADJACENT SAID DUCT MEANS FOR CONTROLLING OPENING AND CLOSING OF THE SAID CHANNELS, SAID CHANNEL BETWEEN THE REAR PORTION OF THE HEAT EXCHANGE ELEMENT AND THE OUTER JACKET BEING PROXIMATE THE REAR PORTION OF THE HEARTH TO ENABLE COMBUSTION GAS PRODUCED DURING OIL FIRING TO PASS AT LEAST IN PART IN THE LATTER SAID CHANNEL WHEN THE LATTER IS OPENED BY THE FLAP MEANS. 